Rotary action latches which have a latching arm operated by handle rotation of a shaft are commonly used as closing mechanisms for doors in applications such as metal cabinets and truck bodies. A shaft of the latch is positioned to intersect a latch mounting body, with a handle attached to the shaft on an exterior side of the body, and the latching arm attached to the shaft on an interior side of the body. The shaft is typically supported in such a position by intersection with a bracket welded to the interior side of the body. Locking rotary latches typically use a key cylinder operated locking slide intersected by the shaft to prevent rotation of the shaft when a flat-sided opening of the locking slide is advanced to be adjacent to a flat-sided section of the shaft. The locking slide is commonly secured to and guided against the interior of the body by a bracket welded to the body over the slide. The body is attached directly to a door.
In latches of this type, the structural integrity and maximum strength of the latch is highly dependent upon the strength of the brackets which secure the shaft and the locking slide to the body. For example, linear and moment forces applied to the shaft, such as applied by the latch arm to the shaft when a latched door is pried, tend to displace the axis of the shaft away from perpendicular intersection with the housing, causing the latch to deflect. A force sufficient to draw the shaft through the housing will of course result in failure of the latch. Torquing forces applied to the shaft through the handle apply moment forces to the locking slide which is resisted at the points of attachment of the brackets which secure the locking slide to the body.
Cleveland Hardware and Forging Company Single Point T-Handle Latch Model Nos. 9001 and 9002 utilize a shaft receiving bracket welded to the interior of the body which supports the end of the shaft on the interior of the body. U.S. Pat. No. 4,706,478 discloses a locking rotary latch which uses several brackets welded to the interior wall of the body, one of which is intersected by the shaft and serves as a guide channel for a locking slide. The use of such brackets in connection with the shaft, latching arm, locking mechanism and mounting body complicates design and assembly, blemishes the exterior of the body where welded, and adds significantly to production cost. Furthermore, the presence of a shaft mounting bracket on the interior side of the body increases the internal dimensional profile of the latch, taking up interior space and requiring a thicker door profile, and limits the radial range of remote latch control rods connected to the latch.